1. Field of the Invention
The present invention relates to an arresting/release device for a swing catch of a working current door opener with a catch lever, which arrests or releases the swing catch, a first safety lever, which keeps the catch lever in the arrested position and is pivotable with the aid of an electromagnet into a position releasing the catch lever, and with a second safety lever, which acts on the safety lever for the impact protection of the catch lever.
Electric door openers are generally known and of a standard nature. A distinction is made between working and no-load current designs. Fundamentally the function of the electric door opener is based on the fact that a changer or catch lever is held by a first safety lever acting as the armature of an electromagnet in the pivoting area of the swing catch of the door opener, until in the case of energization of the electromagnet the safety lever is actuated and adjusted accompanied by the release of the catch lever and therefore the swing catch.
Working current door openers have an unlocking tendency in the case of shocks, vibrations and sudden force action, in that the safety lever is disengaged from the catch lever and the swing catch is released. The otherwise reliably and securely operating working current door openers can only be used to a limited extent or not at all in working environments where there is a vibration hazard, e.g. in vehicles used for transporting money or heavy steel doors.
2. Description of the Related Art
EP 279 878 A1 discloses an arresting/release device with an impact preventer, which comprises a second safety lever for locking a first safety lever referred to as the inner armature, as well as a further safety lever referred to as the outer armature. The second safety or locking lever is articulated in the pivot pin of the changer or catch lever and extends with a control edge and a detent, which cooperate with the safety levers referred to as the inner and outer armatures, over and beyond the locking lever. On energizing an electromagnet the outer armature acting on the control edge firstly deflects the locking lever, releases the locking system and after a predeterminable advance takes with it the inner armature for releasing the catch lever.
The arresting/release device of DE 44 18 863 C1 has two safety levers designed in an opposing manner and which cooperate with a nose on the changer. The first safety lever is constructed as an alternate or two-way arm of the armature of an electromagnet and is provided with a nose, which in the arrested state engages in blocking manner on the changer nose constructed in opposing manner. In the release state the first safety lever is deflected from its rest position towards the changer pivot axis, so that both noses engage behind one another in complimentary manner and have a releasing action. The second safety lever pivotably arranged on the first safety lever and resiliently biased against the changer, cooperates by means of a control edge with the changer in such a way that it is deflected by the changer in scissor-like manner in the case of a deflection of the first safety lever into the open position. The changer with nose can then pass between the stop on the second safety lever and the nose on the first safety lever. Impact on the housing leads to an equidirectional deflection, but not to a spread-apart position, so that at least one of the two safety levers maintains the arresting function.
These known arresting/release devices with impact preventer function reliably and securely. However, they are relatively complicated as regards manufacture and installation due to the design.